West Indies completed an unbelievable comebackAustralia suffered a sensational batting collapse to help West Indies win the first T20I by 18 runs. In a low-scoring encounter, the Aussies looked to be cruising home at the halfway stage of the chase. However, some inspired bowling from the West Indies ensured they stole victory from the jaws of defeat.Andre Russell's maiden half-century helped West Indies post what seemed to be a below-par total of 145 in their allotted 20 overs. However, the likes of Hayden Walsh Jr. and Obed McCoy were simply stunning and helped trigger a collapse for the ages as Australia lost their last six wickets for just 21 runs.Twitter reacts to Australia's sensational collapseFans on Twitter hailed the West Indies for the spirit they showed despite being without their skipper Kieron Pollard. Many also trolled Australia for letting another T20I that was in their grasp slip away. Here's what the fans had to say:Chasing 146 runs, Australia was 108 for 4 from 10.2 overs and bowled out for 127 runs from 16 overs - same old Australia with the collapse in middle-lower order after a terrific start from top-order. #WIvAUS— Johns. (@CricCrazyJohns) July 10, 2021What a Incredible Win by West Indies, What a Comeback. This is Brilliant from Windies bowlers. Australia at one point 108 for 4 In 10.3 overs and needs 37 runs from 57 Balls. But West Indies comeback own their styles. Remarkable Win by 18 runs against Australia. #WIvAUS pic.twitter.com/Vgh7hhY5pV— CricketMAN2 (@man4_cricket) July 10, 2021- Without their injured captain- 53 for 3 after 10 overs with the bat- Opposition need four an over with six wickets in handPretty remarkable victory for West Indies#WIvAUS— Andrew McGlashan (@andymcg_cricket) July 10, 2021Australia needed only 38 from 58 with 6 wickets in hand,only made 19. Not many teams would have been able to defend this ,but West Indies is a terrific all-round side & you are right McCoy was really good and bamboozled the Aussies with his back of the hand slower ones. #WIvsAUS https://t.co/QY5ea3G5Wl— Venkatesh Prasad (@venkateshprasad) July 10, 2021Erm... what just happened there? 😕 #WIvsAUS— Kritika Naidu (@Kritzika) July 10, 2021Australian players after 1st T20 with West Indies :-#WIvsAUS pic.twitter.com/pFbThBxlVz— Funny Boy (@FunnyBoy9102) July 10, 2021What a turnaround by West Indies to defeat Australia. Mccoy is here to stay. #Cricket #WIvsAUS #AUSvWI #IndianCricketTeam #INDvSL— Cricketcasm (@cricketcasm) July 10, 2021Some people still believe Australia will win the t20 WC. We won't go past the group stage this year, I am so sure!!!#WIvsAUS— aay 🦄 (@_kawaaai) July 10, 2021Waking up to an Aussie collapse is always a nice feeling. #WIvsAUS— Mujtaba Ibrahim (@Mujtaba023) July 10, 2021Aus making measurable progress in T20Is. In 2005 they lost 6-5 in a match, and five years later, a 6-10. Today's 6-19 is distinct improvement.— Ric Finlay (@RicFinlay) July 10, 2021Australia got off to a near perfect start thanks to a blistering 33-run cameo from Matthew Wade and a maiden T20I fifty from their new No.3 Mitchell Marsh. They did lose a few wickets but crossed the 100-run mark after just 9.2 overs. At the 10.2 over mark, they needed just another 38 runs with six wickets in hand.McCoy, who has been simply brilliant of late for the West Indies, stepped up once again with a brilliant four-wicket haul. Between him and Walsh Jr., they picked up seven wickets and Australia were bowled out for a meagre 127 runs.The way West Indies celebrated after the win displayed just how much it meant to them. It will certainly boost their confidence ahead of the T20 World Cup in October-November this year as well. Australia, although without a number of their first-team players, would have backed themselves to chase down the target. They now have plenty to think about going forward in the series.The nature of the loss would have hurt their morale and more questions will now be asked of coach Justin Langer and skipper Aaron Finch about where their team is heading on the whole. Australia will hope to recover their mojo ahead of the second T20I on July 11.